Lens comprising a plurality of optical element disposed in a housing

Abstract

The invention relates to a lens comprising several optical elements that are disposed in a lens housing. At least one sensor array encompassing at least one capacitive sensor unit and/or at least one inductive sensor unit is provided for determining the relative position between a first optical element and a second optical element or between a load-bearing structural element of the lens and a second optical element.

The invention claimed is: 
     
       1. A lens, comprising:
 a housing; 
 a plurality of optical elements disposed in the housing, the plurality of optical elements comprising first and second optical elements; 
 a first sensor arrangement comprising an electrode; and 
 a substrate supporting the electrode, 
 wherein the first sensor arrangement is configured to determine a relative position between: a) the first optical element and the second optical element; and/or b) the second optical element and a load-bearing structural element of the first optical element. 
 
     
     
       2. The lens of  claim 1 , wherein first sensor arrangement comprises a capacitive sensor unit, and the capacitive sensor unit comprises the electrode. 
     
     
       3. The lens of  claim 1 , wherein first sensor arrangement comprises an inductive sensor unit, and the inductive sensor unit comprises the electrode. 
     
     
       4. The lens of  claim 1 , wherein the first sensor arrangement is configured so that, during use of the lens, the sensor arrangement determines the relative position in both directions in a horizontal plane perpendicular to a beam direction. 
     
     
       5. The lens of  claim 1 , wherein the first sensor arrangement is configured to determine the relative position between the second optical element and the load-bearing structural element of the first optical element. 
     
     
       6. The lens of  claim 5 , wherein the load-bearing structural element of the first optical element comprises the housing. 
     
     
       7. The lens of  claim 1 , further comprising second and third sensor arrangements, wherein each of the first, second and third sensor arrangements comprises a capacitive sensor arrangement. 
     
     
       8. The lens of  claim 7 , wherein the first, second and third sensor arrangements are arranged at uniform distances around the first optical element and/or the second optical element. 
     
     
       9. The lens of  claim 1 , wherein the second optical element is exchangeable. 
     
     
       10. The lens of  claim 1 , wherein the second optical element is an exchangeable terminating optical element of the lens. 
     
     
       11. The lens of  claim 10 , wherein the first optical element is an optical element arranged upstream of the exchangeable terminating optical element in a direction of an optical axis of the lens. 
     
     
       12. The lens of  claim 11 , wherein the first optical element is fixed relative to the housing. 
     
     
       13. The lens of  claim 12 , further comprising a second sensor arrangement. 
     
     
       14. The lens of  claim 13 , wherein each of the first and second sensor arrangements comprises four capacitive sensor units. 
     
     
       15. The lens of  claim 14 , wherein the first sensor arrangement is oriented relative to the lens, and the second sensor arrangement is disposed in a fixed position relative to the first sensor arrangement. 
     
     
       16. The lens of  claim 1 , wherein the first optical element is fixed relative to the housing. 
     
     
       17. The lens of  claim 1 , wherein the substrate is ring-shaped, and the first sensor arrangement is disposed on the substrate. 
     
     
       18. The lens of  claim 17 , wherein the substrate comprises a material having a low coefficient of thermal expansion. 
     
     
       19. The lens of  claim 17 , wherein the substrate comprises a material selected from the group consisting of glass, ceramic, quartz and glass ceramic. 
     
     
       20. The lens of  claim 1 , wherein the substrate comprises a material having a low coefficient of thermal expansion. 
     
     
       21. The lens of  claim 1 , wherein the substrate comprises a material selected from the group consisting of glass, ceramic, quartz and glass ceramic. 
     
     
       22. The lens of  claim 1 , wherein the lens is a microlithography projection lens. 
     
     
       23. The lens of  claim 1 , wherein the lens is an immersion microlithography projection lens. 
     
     
       24. The lens of  claim 1 , wherein the electrically insulating substrate is ring-shaped. 
     
     
       25. The lens of  claim 1 , wherein the electrode comprises an electrically conducting material. 
     
     
       26. The lens of  claim 1 , wherein the electrode comprises metal. 
     
     
       27. The lens of  claim 1 , wherein the first sensor arrangement is configured to determine the relative position between the first optical element and the second optical element. 
     
     
       28. An apparatus, comprising:
 an illumination system; and 
 a lens according to  claim 1 , 
 wherein the apparatus is a projection exposure apparatus. 
 
     
     
       29. A method of using a projection exposure apparatus comprising an illumination system and a lens, the method comprising:
 using the illumination system to illuminate a mask; and 
 using the lens to project an image of the illuminated mask onto a light-sensitive material, 
 wherein the lens comprises a lens according to  claim 1 . 
 
     
     
       30. A method, comprising:
 a) providing a lens, comprising:
 a housing; 
 a plurality of optical elements disposed in the housing, the plurality of optical elements comprising first and second optical elements; 
 a first sensor arrangement comprising a first electrode; 
 second sensor arrangement comprising a second electrode; and 
 a substrate supporting the first and second electrodes; 
 
 b) using the first sensor arrangement to determine a position of the first sensor arrangement relative to the first optical element or to the housing; 
 c) after b), using the second sensor arrangement to determine a position of the second optical element relative to the second sensor arrangement; and 
 d) after c), using information from b) and c) to determine a position of the second optical element relative to the first optical element or to the housing. 
 
     
     
       31. The method of  claim 30 , wherein the second optical element is a terminating optical element of the lens. 
     
     
       32. The method of  claim 31 , wherein the first optical element is fixed relative to the housing, and the method further comprises positioning the second optical element via a positioning device comprising force-controlled manipulators in six degrees of freedom based on the relative position of the terminating element with respect to the first optical element. 
     
     
       33. The method of  claim 30 , wherein the first optical element is fixed relative to the housing, and the method further comprises positioning the second optical element via a positioning device comprising force-controlled manipulators in six degrees of freedom based on the relative position of the terminating element with respect to the first optical element.